Provided is a three-directional motion decoupling periodic structure for a shaking table container. The periodic structure is formed by sequentially superimposing n periodic structure units, wherein each of the periodic structure units is formed by sequentially superimposing a first side-confining layer, a planar decoupling layer, a second side-confining layer and an elastic layer, wherein n is a positive integer greater than or equal to 2; the cross-sectional shapes of the first side-confining layer, the elastic layer, the second side-confining layer and the planar decoupling layer are the same; and the periodic structure is used for implementing three-directional motion decoupling in the operating condition of ground shaking. Further provided is a three-directional motion decoupling container for shaking table test, which is formed by combining the periodic structure, a container base plate and a position-limiting protection door-type frame (3). The container, which is light in weight and high in strength, is applicable to the shaking table tests at hypergravity and normal gravity. Multiple measures are taken to ensure the motion synchronization between the container and tested soil, the non-interference of the motions of the container and the tested soil in the three directions of X, Y and Z, no extra acting force being exerted on the tested soil by the container, and the avoidance of a boundary effect as much as possible, so as to fully realize the three-directional decoupling and reconstitute original site characteristics.

Provided is a three-directional motion decoupling periodic structure for a shaking table container. The periodic structure is formed by sequentially superimposing n periodic structure units, wherein each of the periodic structure units is formed by sequentially superimposing a first side-confining layer, a planar decoupling layer, a second side-confining layer and an elastic layer, wherein n is a positive integer greater than or equal to 2; the cross-sectional shapes of the first side-confining layer, the elastic layer, the second side-confining layer and the planar decoupling layer are the same; and the periodic structure is used for implementing three-directional motion decoupling in the operating condition of ground shaking. Further provided is a three-directional motion decoupling container for shaking table test, which is formed by combining the periodic structure, a container base plate and a position-limiting protection door-type frame (3). The container, which is light in weight and high in strength, is applicable to the shaking table tests at hypergravity and normal gravity. Multiple measures are taken to ensure the motion synchronization between the container and tested soil, the non-interference of the motions of the container and the tested soil in the three directions of X, Y and Z, no extra acting force being exerted on the tested soil by the container, and the avoidance of a boundary effect as much as possible, so as to fully realize the three-directional decoupling and reconstitute original site characteristics.

An elastic material vibration test apparatus includes a lower support plate having an upper surface on which an elastic material to be tested is placed, an upper support plate disposed above the lower support plate to be spaced apart from the lower support plate, a pillar connecting the lower support plate and the upper support plate, a pressing rod configured to pass through the upper support plate and ascend and descend in a vertical direction, an air bearing installed on the upper support plate and supporting an outer surface of the pressing rod in a non-contact state, a pressing plate coupled to a lower end of the pressing rod to press an upper surface of the elastic material, and one or more weights coupled to the pressing rod above the air bearing.

An elastic material vibration test apparatus includes a lower support plate having an upper surface on which an elastic material to be tested is placed, an upper support plate disposed above the lower support plate to be spaced apart from the lower support plate, a pillar connecting the lower support plate and the upper support plate, a pressing rod configured to pass through the upper support plate and ascend and descend in a vertical direction, an air bearing installed on the upper support plate and supporting an outer surface of the pressing rod in a non-contact state, a pressing plate coupled to a lower end of the pressing rod to press an upper surface of the elastic material, and one or more weights coupled to the pressing rod above the air bearing.

A method for testing a rotor blade of a wind turbine may include predefining a setpoint bending moment distribution. At least two active load-introducing means may be provided which each engage on a load frame. A first of the at least two active load-introducing means may be configured for introducing load in a pivot direction of the rotor blade and a second of the at least two active load-introducing means may be configured for introducing load in an impact direction of the rotor blade. Also provided is at least one passive load-introducing means. A cyclic introduction of load is effected by the at least two active load-introducing means, where a load introduction frequency of the first active load-introducing means and a load introduction frequency of the second active load-introducing means are selected such that the ratio thereof is rational. A testing device for carrying out the method is also provided.

A vibration generation device which can vibrate in only one axial direction is used to simultaneously load a vibration force in a plurality of axial directions onto a test piece, and to make it possible to easily modify the proportion of vibration force in each axial direction. The present invention includes: a vibration generation device connection part 1 which is connected to the vibration generation device and is vibrated in a z-axis direction; a first diaphragm 2 which is connected to the vibration generation device connection part 1 and extends in cantilevered form in an x-axis direction intersecting the z-axis direction; a second diaphragm 3 which is connected to the vicinity of an end of the first diaphragm 2 in the x-axis direction, and which extends in cantilevered form in the z-axis direction and a y-axis direction intersecting the x-axis direction; and a test piece installation part 5 on which the test piece is installed and which receives vibrations via the first diaphragm 2 and the second diaphragm 3 from the vibration generation device connection part 1, wherein at least one of the first diaphragm 2 and the second diaphragm 3 has a length adjustment mechanism 6.

A vibration generation device which can vibrate in only one axial direction is used to simultaneously load a vibration force in a plurality of axial directions onto a test piece, and to make it possible to easily modify the proportion of vibration force in each axial direction. The present invention includes: a vibration generation device connection part 1 which is connected to the vibration generation device and is vibrated in a z-axis direction; a first diaphragm 2 which is connected to the vibration generation device connection part 1 and extends in cantilevered form in an x-axis direction intersecting the z-axis direction; a second diaphragm 3 which is connected to the vicinity of an end of the first diaphragm 2 in the x-axis direction, and which extends in cantilevered form in the z-axis direction and a y-axis direction intersecting the x-axis direction; and a test piece installation part 5 on which the test piece is installed and which receives vibrations via the first diaphragm 2 and the second diaphragm 3 from the vibration generation device connection part 1, wherein at least one of the first diaphragm 2 and the second diaphragm 3 has a length adjustment mechanism 6.

System and methods for characterizing a response of a structure-under-test to applied excitation forces using a test fixture. The fixture is selectively coupleable to the structure-under-test and is configured to hold the structure-under-test at a known position and in a known orientation relative to the fixture. A plurality of excitation devices and response sensors are coupled to the fixture. Excitation forces applied to the fixture by the excitation devices are conveyed by the fixture to the structure-under-test and each response sensor measures a dynamic response indicative of a response of the structure-under-test and the fixture to the applied excitation force. A controller receives response sensor data and applies a mathematical coordinate transformation to project the forces and moments corresponding to the applied excitation and the measured dynamic responses to a target point of the structure-under-test and to calculate a system response function based at least in part on the projection.

System and methods for characterizing a response of a structure-under-test to applied excitation forces using a test fixture. The fixture is selectively coupleable to the structure-under-test and is configured to hold the structure-under-test at a known position and in a known orientation relative to the fixture. A plurality of excitation devices and response sensors are coupled to the fixture. Excitation forces applied to the fixture by the excitation devices are conveyed by the fixture to the structure-under-test and each response sensor measures a dynamic response indicative of a response of the structure-under-test and the fixture to the applied excitation force. A controller receives response sensor data and applies a mathematical coordinate transformation to project the forces and moments corresponding to the applied excitation and the measured dynamic responses to a target point of the structure-under-test and to calculate a system response function based at least in part on the projection.

An apparatus for carrying out load testing on an aircraft part is described. In one aspect, the apparatus includes means for constraining the aircraft part and a linear actuator for applying a test load. The linear actuator has a first part being tiltable and being pivotally constrained about a first and a second geometrical axes, orthogonal to one another, and a second part being slidably mounted on the first part to slide along a longitudinal direction. A load cell, mounted on the second part, measures force acting on the aircraft part along the longitudinal direction. In one aspect, a first clinometer and a second clinometer are mounted on the linear actuator, each clinometer measuring a respective angle representative of rotation of the linear actuator respectively about the first and second geometrical axes. A displacement transducer measures sliding of the second part relative to the first part of the linear actuator.